Messages in this thread | | | Subject | Re: [PATCH v2 5/6] i2c: i2c-stm32f7: Add DMA support | From | Pierre Yves MORDRET <> | Date | Wed, 4 Apr 2018 10:20:44 +0200 |
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On 04/03/2018 05:39 PM, Wolfram Sang wrote: > >> +#define STM32F7_I2C_DMA_LEN_MIN 0x1 > ... > >> + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) { > > Are you using DMA for every message with a length >= 1? The setup of > that might be more expensive than the DMA gain, if so. > Well yes. I am in charge of DMA IPs as well. I2C is the only devices that I had to test DMA outside standard DMA Engine test. Quite convenient. I believe to stress both I2C and DMA, this value was relevant. Now I agree this value can be tuned a little bit. I might raise this threshold in V3.
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